TW200304307A - Data transmission with non-uniform distribution of data rates for a multiple-input multiple-output (mimo) system - Google Patents

Abstract

Techniques to determine data rates for a number of data streams transmitted via a number of transmission channels (or transmit antennas) in a multi-channel (e.g., MIMO) communication system. In one method, the "required" SNR for each data rate to be used is initially determined, with at least two data rates being unequal. The "effective" SNR for each data stream is also determined based on the received SNR and successive interference cancellation processing at the receiver to recover the data streams. The required SNR for each data stream is then compared against its effective SNR. The data rates are deemed to be supported if the required SNR for each data stream is less than or equal to its effective SNR. A number of sets of data rates may be evaluated, and the rate set associated with the minimum received SNR may be selected for use for the data streams.

Description

200304307 发明 玖, description of the invention, (the description of the invention should state: the technical field to which the invention belongs, prior art, content, embodiments, and a simple description of the drawings) Technical Field The present invention is generally related to data communications, and is particularly used to determine One of the data transmission rates used by the plurality of data streams transmitted through a plurality of transmission channels of a multi-channel communication system, such as a multiple-input multiple-output (MulHpldnput Multiple-Output; MILM) system, is unevenly distributed. Prior art In a wireless communication system, a radio frequency modulated signal from a transmitter can reach a receiver via several propagation paths. The characteristics of these propagation paths often change over time due to several factors such as signal attenuation and multipath effects. In order to provide diversity that resists adverse path effects and improves characteristics, multiple transmit and receive antennas can be used. If the propagation path between the transmitting and receiving antennas is linearly independent (that is, the transmission on one path is not formed as a linear combination of the transmission on the other path) 'This situation is usually true at least to some extent, As the number of antennas increases, the probability of correctly receiving a data transmission will also increase. As the transmission and reception antennas increase, diversity will increase and performance will improve. Xizhong input multiple output (ΜΙΜΟ) communication system uses for data transmission, Xi (Nτ) transmission antennas and multiple (Nr) receiving antennas. A MIMO channel composed of% transmission% 、, 泉, and NR receiving antennas can be decomposed into Ns independent # 1 communication channels, where Ns S min {NT, Nr}. Each of these Ns siblings can also be referred to as a spatial subchannel of the MIMO channel, and the independent 200304307 (2) I description of the invention continues the channel corresponding to a dimension. If the use of multiple transmit and receive antennas results in additional scalability, the MIMO system can provide better performance (for example, greater transmission capacity). For a full-rank MIMO channel (where Ns == NtsNr), an independent data stream can be transmitted from each of these Nτ transmission antennas. The transmitted data streams may or may encounter different channel sinks (for example, different signal attenuation and multipath effects), and may obtain different signal to noise and interference ratios at a specific transmission power level Rati0; SNR for short). In addition, if a continuous interference cancellation process is used at the receiver in order to reply to the transmitted data stream (which will be explained later), each data stream can have a different SNR according to the specific order of the data stream reply. Therefore, different data streams can support different data transmission rates according to the snr they present. Because channel conditions usually change over time, the data transfer rates supported by each stream also change over time. If the characteristics of the MIMO channel are known on the transmitter (for example, the SNR presented by the data stream), the transmitter can determine a specific shell material transmission rate and coding and modulation architecture for each data stream, so that the The data stream, resulting in an acceptable performance level H, is not available on the transmitter for some MIMO systems. However, it is alternatively possible to obtain a very limited amount of information such as the working SNR of the MIM0 channel (which can be defined as the expected SNR of all data streams on the receiver). In this case, the transmitter will need to determine the appropriate data transmission rate and coding and modulation architecture for each data stream based on the limited information. 200304307 Description of Invention Continued (3) Therefore, ‘this technology needs a technology to determine a set of data transmission rates for multiple data streams when the MIm0 channel transmitter can only obtain limited information in order to achieve performance. SUMMARY OF THE INVENTION The present invention provides some techniques for providing better performance when the channel state information used to indicate the current channel condition cannot be obtained on the transmitter. In one aspect, a uniform cloth of data transmission rate is used for the transmitted data stream. The data transmission rate can be selected in order to achieve: a low overall "receive" snr (explained below) with a specified overall spectral efficiency; or a good reception SNR There is a higher overall spectral efficiency. The present invention provides a specific architecture for achieving each of these goals. In a specific embodiment that can be used to achieve the above-mentioned first objective, a method is provided for determining a data transmission rate for a plurality of data streams to be transmitted through a plurality of transmission channels of a multi-channel communication system (for example, A data stream can be transmitted via each transmission antenna in a MIMO system). According to this method, it is determined at the beginning that each data transmission rate to be used for these data streams must be snr per data transmission rate. At least two of these data transmission rates are different. Also based on the received SNR and the successive interference cancellation processing performed on the receiver in order to reply to these data streams (to be described below), the "effectiveness" of each data stream is determined, and snr (also It also explains). Then the required snr of each data stream is compared with the 2-effect SNR of the data stream. If the required snr of each data stream is less than or equal to the effective SNR of the data stream, it is deemed to support such data streams Data transmission rate. May 200304307 'Description of the invention The continuation page evaluates several groups of data transmission rounds and calls on W Fanfeng, and selects the rate group associated with the minimum receiving MR for use in such data streams. In a specific embodiment of the above-mentioned second objective, a data transmission rate for determining a number of data streams to be transmitted through a plurality of transmission channels (such as transmission antennas) of a multi-channel (such as M1M0) communication system is provided. Method. According to this method, the reception is decided at the beginning. The reception SNR can be specified for the system, or the reception SNR can be estimated based on the measured value on the receiver, and the reception SNR can be improved. To transmit ^. Also determine the effective SNR of each data stream based on the received SNR and the continuous interference cancellation processing on the receiver. Then determine the data transmission rate of the data stream based on the effective SNR of each data stream, at least The two data transmission rates are different. The various aspects and embodiments of the present invention will be further described below. As will be further described below, the present invention further provides various aspects, embodiments, and embodiments for implementing the present invention, and Some methods, processors, transmitter units, receiver units, base stations, terminals, and other devices and components. Embodiments can be implemented in various multi-channel communication systems to determine based on limited channel state information The technology of the present invention for a set of data transmission rates of multiple data streams. This multi-channel communication system includes a multiple-input multiple-output (MIMO) communication system, and Orthogonal Frequency Division Multiplexing (OFDM for short) communication. System, and MIMO system using OFDM (ie, MIM0-〇FDM system) Communication system. 200304307 (5) Continued description of the invention In order to take account of the clarity of the description, various aspects and embodiments will be specifically described for the mim〇 system. A MIMO system uses multiple (Nτ) transmission antennas and multiple (known) Receiving antenna 'for data transmission. A MIMO channel composed of ^ transmitting antennas and ^ receiving antennas can be broken down into Ns independent channels, of which NsSmm {NT, NR}. Each—the Ns independent The channel is called a spatial subchannel of the MIMOM pass. The number of characteristic modes of the mim0 channel determines the number of spatial subchannels, and the number of characteristic channels of the μm A channel response matrix to describe the response between the equalized transmission antennas and the NR receiving antennas is composed of several independent Gaussian random variables {hi j}, each element of the channel response matrix 氐, where 丨 = 1, 2 , ... NR, jn ·· &, and is the light coupling (ie, the complex gain) between the 传输 th transmitting antenna and the ith receiving antenna. For the sake of clarity, suppose that the channel response matrix is full-ranked (that is,

(Ns = NTSNR), and can be added from each reading, and the Nτ transmission antennas in Muju Temple transmit an independent data stream. FIG. 1 is a block diagram of an embodiment of a transmitter system (110) and receiver system (150) in a MIMO system (100). In the transmitter system (110), the communication data of the thousands of data streams is provided from a data source (112) to a transmission (TX, data) processor (114). In one embodiment, each data stream is transmitted via a separate transmitting wheel antenna. T) > The material processor (114) formats, encodes, and interleaves the communication data of the data stream according to a specific encoding architecture selected for each lean stream to provide the encoded data . 200304307 Description of the Invention Continued 多 Multiplexed coded data and pilot data of each data stream can be multiplexed using, for example, Time Division Multiplexing (TDM) or Code Division Multiplexing (CDM) . The pilot data is usually a known data pattern that is processed in a conventional manner (if this is the case), and the pilot data can be used at the receiver to estimate the channel response. Then tune (that is, perform symbol M mapping) the multiplexing of the data stream according to a specific modulation architecture_ (such as BPSK, QPSK, M-PSK, or M-QAM) selected for each data stream The pilot data and coded data φ φ to provide modulation symbols. Each control unit provided by the controller (130) can determine the data transmission rate, coding, and modulation of each data stream. The modulation symbols of all data streams are then provided to a transmission (TX) MIMO processor (120), which can further process the modulation symbols (such as those of OFDM). The TX MIMO processor (120) then provides Nτ modulation symbols to Nτ transmitters (TMTR) (122a-122t). Each transmitter (122) receives and processes a separate symbol stream to provide one or more analog symbols, and further adjusts (e.g., amplifies, filters, and upconverts) the 0 analog symbol to provide a suitable The modulated signal transmitted via the MIMO channel. The Nτ modulated signals from the transmitters (122a-122t) are then transmitted from the Nτ antennas (124a-124t), respectively. In the receiver system (150), NR antennas (152a-152r) receive the modulated signals transmitted and provide the received signals from each antenna (152) to a separate receiver (RCVR ) (154). Each receiver (154) adjusts (eg, filters, amplifies, and downconverts) a respective signal received, digitizes the adjusted signal to provide samples, and further processes the -10- 200304307 invention Description Continued ⑺ Sample to provide a corresponding "receive" symbol stream. A receive (RX) MIMO / data processor (160) then receives NR received symbol streams from NR receivers (154), and processes the NR received symbol streams according to a specific receiver processing technique to provide Ντ "detected, symbol streams. The processing performed by the RX MIMO / data processor (160) will be described in further detail below. Each detected symbol stream includes data transmitted for the corresponding data stream. The symbol of the estimated value of the modulation symbol. The RX ΜΜΜΟ / data processor (160) then demodulates each detected symbol stream, interleaves, and decodes it in order to restore the communication data of the data stream. RX ΜΙΜΟ / The processing performed by the data processor (160) is complementary to the processing performed by the TX MIMO processor (120) and the TX data processor (114) on the transmitter system (110). The RX MIMO processor (160) may For example, an estimated value of the channel response between the Nτ transmission antennas and the NR receiving antennas is derived based on the pilot data multiplexed with the communication data. The estimated value of the channel response can be used on the receiver to perform emptying. Or space / time processing. The RX MIMO processor (160) can further estimate the signal-to-noise and interference ratio (SNR) of the detected symbol stream, and possibly other channel characteristic values, and provide these quantized data to a Controller (170). The RX MIMO / data processor (160) or controller (170) may further be used to indicate the status of the communication link "working" SNR estimate. The controller (170) then provides the channel Channel state information (CSI for short), the channel state information may include various information related to the communication link and / or the received data stream. For example, the CSI may only include the working SNR. The CSI is then Transmission (TX) data processor (178) 200304307 (8) Description of the invention Continuation page processing, which is modulated by a modulator (180), adjusted by a receiver (154a-154r), and transmitted by a cycle transmitter system (110 On the transmitter system (110), the modulated signal from the receiver system (15) is received by each antenna (124), adjusted by each transmitter (122), and decoded by a demodulator (140). Tuned and received by a receiver (RX) The processor (142) processes in order to reply the CSp reported by the receiver system and then provides the reported CSI to the controller (130), and the mirror uses the reported CSI to: (1) decide to be used for such data streams Data transmission rate, encoding and modulation architecture; and (2) production of various controls on the TX data processor (114) and τχ ΜΜΟ processor (120). The controllers (130) and (170) instruct the transmitter respectively And the operation on the receiver system. The memory (132) and (172) provide storage space for the codes and data used by the controllers (130) and (170), respectively. The model of the MIMO system can be expressed as: (Equation 1) where 3L is the receiving vector, that is, y ^ [yi y2_yNR] T, where is the data item received on the first receiving antenna, and iei ... .,; X is a transmission vector, that is, 2L = [Xi χ2 ••• XΝτ] 1 ', where {Xj} is a data item transmitted from the jth transmission antenna, and je {丨, ... , Ϋ is the channel response matrix of the MIMO channel; IL is the additive white Gaussian Noise (AWGN) with an average vector L and a covariance matrix L-σ, where 込Is a zero vector, [is an identity matrix with diagonal elements being one and the other elements being zero, and σ2 is the variable of the noise; and -12- (9) (9) 200304307 Description of the invention continued The page [·] T indicates the transpose of [·]. Due to the scattering in the propagation environment, the N symbol streams transmitted from Nτ transmission antennas will interfere with each other at the receiver. All NR receiving antennas are particularly likely to receive a symbol stream transmitted from a transmitting antenna at different amplitudes and phases. Each signal received may then contain a component of each of these Nτ transmitted symbol streams. The Nr received signals will collectively contain all the transmitted symbol streams. However, these Nτ symbol streams are interspersed among the NR received signals. ~ On the receiver, various processing techniques can be used to process NR received signals' in order to detect Nτ transmitted symbol streams. The processing technologies of these receivers can be categorized into two main types: • space and space-time receiver processing technologies (also known as equalization technologies); and • "continuous write-off / equalization and interference Cancellation, receiver processing technology (also called this technology "continuous interference cancellation," or "continuation cancellation, receiver processing technology". Generally, T, space and space-time receiver processing techniques try to separate the receiver The transmitted symbol stream. It can be combined according to an estimated value of the channel response. Various cutters of the transmitted symbol stream included in the received signal, and (2) remove (or cancel) the other symbol streams. Interference, and detect each transmitted symbol stream. These receiver processing techniques try to de-associate the individual transmitted symbol streams so that there is no interference from other symbol streams, or (2) when there is interference from other When the noise and interference of the symbol stream are maximized, the SNR of each detected symbol stream is maximized. Then proceed to • 13- 200304307 (ίο) Invention Description , Deinterleaving, and decoding) to detect each symbol stream in order to restore the communication data of the symbol stream. The successive cancellation receiver processing technology attempts to use space or space-time receiver processing technology to reply one at a time. The transmitted symbol stream cancels the interference caused by each "recovered" symbol stream, so that the later recovered symbol stream has less interference and can obtain a higher SNR. This 4-continuous cancellation receiver processing technique can be used if the interference due to each symbol stream returned can be accurately estimated and canceled (requiring the symbol stream to be returned without error or low error). This successive cancellation receiver processing technology, which will be described in further detail below, generally outperforms these space and space-time receiver processing technologies. For the successive cancellation receiver processing technology, Nr stages are processed by Nr received symbol streams in order to successively reply to a transmitted symbol stream at each stage. When replying to each transmitted symbol stream, 'the interference caused by the symbol stream to the remaining unrecovered symbol streams is estimated, and the interference is canceled from the received symbol stream, and the "passing" is further processed by the next stage. Modified, symbol stream in order to reply to the secondary / transmitted symbol stream. If such transmitted symbol streams can be recovered without errors (or at least errors), and if the channel response estimates are reasonably estimated, then The cancellation of the interference due to the returned symbol stream is effective 'and improves the SNR of each symbol stream in the subsequent reply. In this way,' all transmitted symbol streams can achieve higher performance (possibly except for the required In addition to the first transmitted symbol stream), the following terms are used in the present invention: 200304307 (11) I Description of the invention & • "Transmitted" symbol stream-a symbol stream transmitted from a transmitting antenna; "Receive , A symbol stream-a successive interference cancellation (SIC) receiver (refer to Figure 6) in one of the first levels of space or space · Inputs to the time processor; • "Modified" symbol streams-input to the space or space-time processor in each subsequent stage of the SIC receiver; • "detected" symbol streams-to the space processor Output (up to NT-k + i symbol streams can be detected on the kth stage; and • "Reply" symbol stream-a symbol stream that has been decoded on the receiver by Uα G (on each stage Only one detected symbol stream is replied.) Figure 2 shows the performance of the offset cancellation receiver's processing technology to process the received symbol streams so as to loop Nτ transmitted symbols, six digits, and fools / watts—flow. In order to simplify the explanation, the following explanation of FIG. 2 assumes that η, Ban Lang [,, the number of two interpasses is equal to the number of billion round antennas (that is, Ns: = n < 1SJ, 'WKNr ), And it is a separate data stream from each transmission. $ ^ Μ For the first stage (k = l), A stops ^ In step (212), the receiver receives NR receivers when the receiver is opened. Is the symbol stream to be handled as openly as the time interval or space_time processing, leaving NR transmission symbols For the first stage, the pEj + time-time processing can provide Nτ detected 侦测, which is the estimated value of N 2 or Ν (neither reply) transmission. % ,, m / watts. Then (such as according to the selected architecture)-select these detected, special and further process the symbol stream. 钆 ★ the identity of the symbol stream transmitted by a, Then, if you want to reply, you can execute the 2 or space-hours, so as to provide only the transmitted symbol hiding, ^ τ] to keep a detected symbol stream. Regardless of -15-(12) 200304307 Description of the Invention Steps for continued page processing (such as demodulation, streaming, in order to obtain a solution which is one of the estimated values, which is the case, in "2 7 Baht (214), all 1 ~ parent interpolation, and decoding) selected ^ The selected detection symbol is the data stream of the data stream code of the reply transmission in this level. Then, in step (216), it is determined whether the b τ ^ ^ policy., Whether or not all the transmitted symbol streams have been replied. If Ai Zhe County orders ΑΑ β to pay ", the processing of the receiver is terminated. Otherwise in step (218) for each received NR received symbol stream

Estimate the interference due to the symbol stream just returned. The interference can be calculated as follows: first re-encode the decoded data stream, then interleave the re-encoded data, and then perform symbol mapping on the interleaved data (using the transmitter unit for the β 'shell stream) The same encoding, interleaving, and modulation architecture) in order to obtain a "remodulated, symbol stream, which is an estimate of one of the transmitted symbol streams just returned. Then calculate The spin product between each element of the NR elements in a channel response vector kj and the re-modulated symbol stream, so as to derive the symbol

Nr interference components generated by the stream. This vector dagger is a row in the (Nr X NT) channel response matrix 1 corresponding to the j-th transmission antenna used for the symbol stream just returned. The vector kj contains Nr elements to define the channel response between the j-th transmission antenna and the NR receiving antennas. Then, in step (220), NR interference components are subtracted from NR received symbol streams, so as to derive NR modified symbol streams. These received symbol streams represent the symbol streams that have been received without previously transmitting the symbol stream that was just returned (that is, assuming that interference cancellation has been effectively performed). Then repeat the process of steps (212) and (214) for Nr modified symbol streams (not Nr received symbols • 16-200304307 (13) Invention Description Continued Page Stream) in order to return to Germany x Your native Let another transmitted symbol stream. Therefore, the steps are repeated for each transmission lacking to be answered.

Steps (212) and (214), and if there is another symbol to be transmitted, steps (218) and (220) are performed. , L For this first stage, the input symbol stream is from N handle η

接收 received symbol streams of Nr receiving antennas. And for each subsequent level, the '%' symbol stream is Nr modified symbol households from the previous level. / I. The processing at each level is continued in a similar manner. De M in the first level >

The mother-level history of 1 cross ^, suppose that the symbol flow returned in the previous levels is canceled, and the dimension of the 遒 ringing matrix 因 is reduced by one in each subsequent level due to ^ U ~ " j 'One line. The continuation cancellation receiver processing thus includes several stages, one stage at a time of transmission of the symbol stream to be returned. Each level returns a pass of the pass% ,, v cash > watts, and (except for the last level) cancels the interference caused by the symbol flow of the reply, in order to get a modified symbol flow for the next level . After

Continued recovery of the symbol stream thus encounters less interference and can achieve a higher SNR than when there is no interference cancellation. The SNR of the returned symbol stream depends on the specific order of the symbol stream reply. For successive cancellation receiver processing, the input symbol stream of the k-th stage (assuming that the interference generated by the symbol stream returned in the previous k-1 stages has been effectively canceled) is expressed as:

Zk = HkXk + n ^ (Equation 2) where ilk is an input vector of NR X of the k-th stage, that is, Zk = [yik y2k · ykNR] T, where yik is the first receiving antenna of the k-th stage Data item; 2Lk is the kth order (Nτ-k + 1) X 1 transmission vector, that is, = [Xk -17- 200304307 Description of the invention continued (14)

Xk + i ... Xnr] T, where {&} is the data item transmitted from the "transmission antenna"; ilk is the NR X (NT-k + 1) channel response matrix of the MIMO channel, where the previous one has been removed The k-1 rows of the returned symbol stream are 'ilk iLk + 1 ... H_Nx], and IL is additive white Gaussian noise. To simplify the explanation, equation (2) assumes that the transmitted symbol stream is returned in the order of the transmission antennas (that is, the symbol stream transmitted from transmission antenna 1 is first returned, and then the symbol stream transmitted from transmission antenna 2 is returned. By analogy, and finally reply to the symbol stream transmitted from the transmission antenna Nτ). Equation (2) can be rewritten as: L · w Equation (3) The transmitted symbol stream to be recovered in the kth stage can be regarded as projected from a disturbing subspace (or plane) f at a specific angle. The transmitted symbol stream is dependent on the channel response vector kk (and is defined by the channel response vector kk). The channel response vector Lk can be projected onto an interference-free subspace orthogonal to the interference subspace to obtain an interference-free result of the transmitted symbol stream. This projection can be obtained by multiplying iLk by a filter with a W response. The filter that reaches the maximum energy after projection is one of the filters located in the primary space composed of iLk and the interference subspace f, where f ^ span (ii i 2 ··· iNT-k), imHin = Sm, n , And {^} (where n = i, 2, ... NT-k) is a normalized orthogonal basis that spans the interference subspace 1: -18-200304307 (15) Yin si] = Zhao Ml IV, but S ', I2] Invention description Continued equation (4) contention-Σ with [16 ^ 1% Μ

Nr-+ k where [Hkk represents the projection of lik on the perturbation-free subspace (that is, the component that is 耑); and ilHkk represents the projection of kk on the interference subspace (that is, the interference component). Equation (4) assumes that the same transmission power is used for these transmission antennas. The effective SNReff (k) of the symbol stream recovered in the k-th stage can be expressed as

Kk,:, Equation 5 where Ptot is the total transmission power available for data transmission, and the total transmission power is evenly distributed across Nτ transmission antennas, so each transmission antenna uses a transmission power of pt〇t / NT; and σ2 Noise is easy to change. The received SNRrx of each received symbol stream of one hundred and one hundred NR is defined as: Combined equation & ^ Equation (6) When the effective SNR table type, (5) and (6), the The symbol “7”, is that the interference (Eq. (7)) has been effectively canceled and is not ready for E »\ iVriV / ?, Wan Cheng Λ (7) and the effective SNR is based on several assumptions. Number _,> The interference caused by the per-received symbol stream, and the noise that can be detected in the symbol stream of subsequent replies -19- (16) (16) 200304307 Invention Description Continued page Excellent. The second 'assumes that there will be no (or very low) errors propagating from one level to the other. The first 5' will use an optimal filter that maximizes the SNR to each detected symbol stream. . Equation ⑺ also provides valid snr expressed in linear units (ie not expressed in log or decibel units). As described in the article, the transmitted symbol stream may encounter different channel conditions, and may have different § dishes at different transmission power levels. If the obtained SNR of each symbol stream is known on the transmitter, the data transmission rate and coding and modulation architecture can be selected for the corresponding data stream, in order to maximize the frequency and the target packet error. Rate (Packet Error Rate, PER for short). However, for some MIM0 systems, channel status information indicating the current channel status is not available on the transmitter. In this case, adaptive rate control of the data stream cannot be performed. Traditionally, in some MIMO systems, when the transmitter cannot obtain the channel state information, the data is transmitted at the same data transmission rate via% transmission antennas (that is, the data transmission rate is evenly distributed). On the receiver, the successive cancellation receiver processing technology can be used to process the received symbol stream. In the traditional architecture, it determines the SNR of the (NT-k + 1) symbol stream detected at each level of k. And in this level, the detected symbol stream with the highest snr is returned. This uniformly distributed wheel architecture with data transmission rates provides sub-optimal performance. The technologies provided by Ben Mingming # provide better performance to the MIM0 system and system when the transmitter cannot obtain the channel status information used to indicate the current channel status. In one aspect, the uneven sentence distribution of data transmission rate is used for the transmitted data stream. The data transmission rate can be selected to achieve -20- (17) (17) 200304307 Description of the invention continued on the following pages: (1) at a lower minimum "receive" SNR, there is a specific white, or specified overall spectral efficiency ; Or (2) at a specific or specified SNR, there is a higher overall spectral efficiency. A specific framework for achieving each of these goals is provided below. We can prove that ... In many cases, the uneven distribution of the data transmission rate is usually better than the uniform distribution of the traditional data transmission rate. Μ As shown in Equation ⑺, the effective system of each symbol stream returned is dependent on the specific level at which the symbol stream is restored (such as in the equation (7) for the molecule ^ "k" 7). The first replying symbol stream gets the lowest effective coffee, and the last replying symbol stream gets the highest effective SNR. In order to obtain better performance, the uniform distribution of the data transmission rate can be used for the data stream according to the effective SNR of the data stream transmitted on different antennas (that is, different spectral efficiency can be assigned to different Transmission = line). On the receiver, the transmitted data stream may be repeated in ascending order of the data transmission rate. That is, 'the data stream with the lowest data transmission rate is returned first', and then the next higher data transmission rate is returned: the data stream, and so on, and the data stream with the highest data transmission is finally returned. The μ 'rate takes into account various factors that need to be considered and determines the data transfer rate that will be used for these data streams. First, as shown in Equation ⑺, an earlier reply to white and symbol streams will result in a lower effective SNR, and further, a lower eight-order diversity order. In fact, the diversity multiplier on the k-th stage can be expressed as (NR-NT + k). In addition, the encoding error from the symbol stream received earlier is propagated to the symbol stream that is returned later, and this may affect this. ~ 21-200304307 (18) Description of the Invention Effective SNR. Therefore, the data transmission rate of the symbol streams returned earlier can be selected, so that a higher degree of trust can be obtained when replying to these symbol streams, and the error propagation (Error Propagation; EP for short) of the symbol streams returned later can be reduced or restricted. effect. Second, if the later-returned symbol streams are specified to support greater spectral efficiency, then these later-recovered symbol streams may be more prone to errors, and even if the later-recovered symbol streams may achieve higher effective SNR in this way. Various architectures can be implemented in order to: (1) determine the minimum received SNR required for a particular distribution of data transmission rate (or spectral efficiency); or (2) decide on a specific received SNR Distribution of spectral efficiency for best performance. A specific architecture for each of these purposes is described below. Figure 3 is a flowchart of a procedure (300) for determining the minimum received SNR required to support a particular set of data transmission rates. The data transmission rate of the group is represented as {rk} ′, where 1,2, ... Nτ, and the order of the data transmission rates is rg ο .. ^ γντ. These data transmission rates in the {rk} group will be used for Nτ data streams to be transmitted from Nτ transmission antennas. At the beginning, it is determined in step (312) that the required snr is used in the receiver to support each data transmission rate (or spectral efficiency) in the ^^ group. The above steps can be completed by using the _query} between SNR and efficiency. Based on the assumption that a single data stream is transmitted via a single input multiple output Dora-Multiple-Output '(SIM0) channel of {1, Nr}, and (such as using computer simulation) is determined—specific spectrum efficiency: necessary Second, and further-it is determined for a specific target per (for example, i% per)-22-200304307 (19) Description of the invention The continuation page determines that the required SNR is required. The required SNR of a data stream with a data transmission rate is expressed as SNRreq (rk). In step (312), a set of Nτ data streams of Nτ data streams must be SNR. Associate the Nτ data transmission rates in the {rk} group with ^ necessary SNRs on the receiver in order to obtain the target PER (for example, use the lookup table to determine the target PER). It is also possible to correlate these Nτ data transmission rates with κ effective SNR and, as shown in Equation ⑺, use the receiver's continuous interference cancellation processing on the receiver to obtain the above-mentioned Relevance. If the Nτ must have an SNR equal to or lower than the corresponding effective SNR, it is considered to support the data transmission rates in the {rk} group. When represented graphically, Nτ points can be drawn with Nτ required SNR and corresponding data transmission rate as the coordinates, and these Nτ points can be connected together by a first line, and Nτ effective points can be drawn The SNR and the corresponding data transmission rate are Nτ points of the coordinates, and these Nτ points are connected together by a second line. If any part of the first line is not above the second line ', it is deemed to support the data transmission rates in the {rk} group. The margin of a specific data transmission rate can be defined as the difference between the effective SNR and the required SNR of the data transmission rate, that is, margin (k) = SNReff (rk) -SNRreq (rk). If the margin of each data transfer rate is equal to or greater than zero, it can also be considered as supporting those data transfer rates in the {rk} group. The effective SNR of these data streams depends on the received SNR, and as shown in Equation ⑺, the effective SNR can be derived from the received SNR. The minimum received SNR required to support & data transmission rates in the {~} group is to make the last -23- (20) (20) 200304307 invention description the effective SNR of the continued page transmission rate is equal to the required SNR (i.e. The margin is the dirty. The specific data transfer rate included in the group k} is obtained, and the (zero) minimum margin is obtained for any one of the group τ data transmission rates—the data transmission rate. In the first iteration, Assume that the minimum margin is obtained by the last-responded data stream, and the index variable λ is set to Nτ (that is, λ = Nτ) in step Π 1 by Qi # 4 »Ρ 艾 骤 (314). Then, In step (316), 'the effective SNR of the 帛 λ recovered data streams is set to be equal to its required SNR (i.e., SNReff (^ = sNR ^^^). In step (318), using equation 方程, according to The effective SNR (ie, SNReff (M)) of the received data stream is used to determine the receiving snr. In the first iteration, when λ = Ντ #, the equation ⑺ can be used to determine the receiving SNR with osmium telluride. The received SNR is expressed as: SNRrx = NT · SNReff (NT) Equation (8) and then in step (320) According to the received snr calculated in step (318), and using equation ⑺ (where k = 1, 2, ... such as-丨), the effective SNR of each remaining data stream is determined. In step (320), ^ Data streams to obtain a set of effective SNRs of Nτ. Then in step (322), the required SNR of each data transmission rate in the {rk} group is compared with the effective SNR of the data transmission rate. Then in step (324) 'determines whether the received SNR determined in step (18) supports the data transmission rates in the {rk} group. Especially if the required SNR for each of these Nτ data transmission rates is less than or equal to the data The effective SNR of the transmission rate is regarded as that the received SNR supports these data transmission rates in the {rk} group and is declared successful in step (326). Otherwise, if Nτ data transmission rates -24- (21) ( 21) 200304307 The invention states that any data transmission rate in the performance page exceeds the validity rate of the data transmission rate, it is deemed that the received SNR does not support these data transmission rates in the group. In this case, in the step Decrement the variable λ in (328) (that is, λ = λ_1 'thereby making λ = Ντ-1 in the second iteration. The procedure then returns to step (3 丨 6)' in order to determine that the minimum-to-the-second response to the data stream achieves this minimum This set of effective SNRs for the data transmission rates in the {r "group under Yu's assumption. Repeat as many times as necessary until success is declared in step (326). Then, the received SNR determined in step (318) in the j response that caused the announcement is the minimum received SNR required to support these data transmission rates in the {rk} group. The procedure shown in Figure 3 can also be used to determine whether a particular received SNR supports a data transmission rate of a special group. This received SNR may correspond to the operating SNR (SNRop), which may be the average or expected (but not necessarily instantaneous) received SNR at the receiver. The working SNR can be determined based on measurements on the receiver, and the working SNR can be provided to the transmitter periodically. In an alternative embodiment, the working SNR may be an estimate of the MIMO channel where the transmitter is expected to operate. In either case, the received SNR is provided or specified for the mim0 system. Referring to FIG. 3, in order to determine whether the specific receiving SNR supports the data transmission rate of the specific group, the necessary SNR of each data transmission rate can be determined in step (3 12) at the beginning. In step (312), a set of Nτ required SNRs is known for nt data streams. Steps (314), (316), and (18)) can be skipped because the receiving snr has been provided. Then in step (32), 'every-based on this particular received SNR and using equation (7) (where k = 1, 2 • 25- (22) 200304307 invention description continuation page ... NT)' is determined. The effective SNR of the data stream. In step ii), a set of Nr valid snr is obtained for NT data streams. Then in step ㈣, each data transmission rate in the group must be compared with the effective data transmission rate. It is then determined in step (324) whether the received SNR supports the data transmission rates in the group. If each of these Nτ data transmission rates must be read less than or equal to the effective SNR of the data transmission rate, it shall be deemed that the receiving Teng supports such data transmission in the {rk} group. John catches the sheep and declares ^ in step (326). Otherwise, 'If any of these ~ data transmission rates-the SNR of the data transmission rate must exceed the data value, weight, Xuan', X, and the effective SNR of the transmission rate, it is deemed that the received SNR does not support { The rk} group of these data transmission rates, and declared that in order to take into account the clarity of the description, an example will be described below for a (2,4} mim〇 system, where the ΜΤΜΠ $ β EI 丄 八 τ ^ ΜΙΜΟ system With two transmitting antennas (ie, τ = 2) and four receiving antennas (also # Nr = 4), and specifying that the system supports 3bpS / Hz (3 bits / Hz) _ the overall spectral efficiency In this example, two groups of data transmission rates are to be evaluated. The first group includes data transmission rates for bpS / Hz and 2bPs / Hz, and the two groups include ^ bps / Hz and 5/3 bps / Hz data transmission rate. Then (such as according to the procedure shown in Figure 3) determine the performance of each rate group ^, and compare these performances with each other 0 1 bps / Hz, 4/3 bps / Hz, PER and SNR Relationship or other ways to generate this. Figure 4 shows a 5/3 bps / Hz, and 2 in a {1,4} ΜΙΜΟ system. The following figure shows the spectral efficiency of 5 卩 3 /; ^. You can use the computer simulation conventionally known in this technology-26-200304307 (23) Description of the continuation of the figure. Usually a MIMO system is designated as a specific target PER In this case, you can determine the SNR required to achieve the target PER at each spectral efficiency and store the SNR in a lookup table. For example, if the target PER is 1%, you can separately For the spectral efficiency of 1, 4/3, 5/3, and 2 bps / Hz, the values of -2.0 dB, 0.4 dB, 3.1 dB, and 3.2 dB are stored in the lookup table. For the first rate group For example, the graphs 412 and 418 in FIG. 4 can be used to determine the necessary SNRs of the data streams 1 and 2 with spectral efficiency of 1 and 2 bps / Hz (step (312) in FIG. 3) as follows: SNRreq (l) =-2.0dB, for data stream 1 with spectral efficiency of 1 bps / Hz; and SNRreq (2) = 3.2dB, for data stream 2 with spectral efficiency of 2 bps / Hz, and then Effective SNR of data stream 2 (the data stream 2 was finally restored under the assumption that the interference caused by data stream 1 has been effectively cancelled) Set it to the required SNR (step (316) in Figure 3), as shown in the following formula: SNReff (2) = SNRreq (2) = 3.2 dB. Then determine the receiving SNR according to equation (8) (step 3 in Figure 3 ( 318)), as shown in the formula: SNRrx = 2 · SNRreq (2), for linear units, or SNRrx = SNRreq (2) + 3.0dB = 6.2dB, for logarithmic units. Then, according to equation (7), the effective SNR of each remaining data stream (ie, data stream 1) is determined (step (32) in FIG. 3), as shown in the following formula: SNReff (l) = 3/8 · SNRrx , For linear units, or -27-200304307 (24) Description of the invention Continued page SNReff (l) = SNRrx-4.3dB = ι · 9dB, used for logarithmic units. The effective and required SNRs for each data rate in the first rate group are provided in rows 2 and 3 of Table 1. The margin for each data transfer rate is also determined and is provided in the last column of Table 1. Table 1 Unit data stream for the first rate group and the second rate group 1 2 1 2 Spectral efficiency 1 2 4/3 5/3 bps / Hz SNReff 1.9 3.2 1.8 3.1 dB SNRreq -2.0 3.2 0.4 3.1 dB decibel margin 3.9 0.0 1.4 0.0 The decibels then compare the necessary SNRs of data streams 1 and 2 with the effective SNR of these data streams (step (322) of FIG. 3). Because SNRreq (2) = SNReff (2), and SNRreq (l) < SNReff (l), a minimum receiving SNR of 6.2 dB supports the data transmission rate of the group. Because the first iteration using the procedure shown in Figure 3 is considered to support the first rate group, no additional iterations need to be performed. However, if a received SNR of 6.2 dB does not support the first rate group (for example, if the required SNR result for data stream 1 is greater than 1.9 dB), another iteration will be performed, and therefore based on SNRreq (l), Decide the receiving SNR. The receiving SNR of JL will be greater than 6.2 dB. For the second rate group, the necessary SNRs of the data streams 1 and 2 with the spectral efficiency of 4/3 and 5/3 bps / Hz can be determined using the graphs 414 and 416 'in FIG. 4, respectively: -28 -200304307 (25) Description of the invention Continuation page SNRreq (l) = 0.4 dB for data stream 1 with a spectral efficiency of 4/3 bps / Hz; and SNRreq (2) = 3.1 dB for 5 / 3 bps / Hz spectral efficiency data stream 2. Then set the effective SNR of data stream 2 to its required SNR. Then, the receiving SNR is determined according to the equation (8), as shown in the following formula: SNRrx—SNRreq (2) +3 · 0dB = 6. 1dB, used for logarithmic units. Then, according to equation (7), the effective SNR of each of the remaining data streams (ie, data stream 1) is determined as follows: SNReff (l) = SNRrx-4.3dB = 18dB, which is used for logarithmic units. The effective and required SNRs for each data transmission rate in the second rate group are provided in Tables 4 and 5). The effective SNRs of data streams 1 and 2 are then compared with the necessary SNR of these data streams. As mentioned before, 'because SNU2) = SNReff (2), and SNRreq⑴ < SNReff (l)', so 6.1dB—the minimum received SNR supports the data transmission rate of this group. The previous description is directed to a “vertical, continuous interference cancellation architecture, so a data stream is transmitted from each transmission antenna, and at the receiver, by processing the data stream from a transmission antenna, A data stream is returned at each level of the machine. The graphics in Figure 4 and the look-up table are derived for the vertical structure. The technology described in the present invention can be applied to a "diagonal line," which continues to interfere Offset architecture, where each-data stream is transmitted from multiple (eg, all) transmission antennas (and possibly across multiple frequency intervals). On the receiver, you can reply to each data stream from the -29- (26) 200304307 Invention Description Continued page on each level of the interference cancellation receiver to the from-transmission antenna number. Use another set of graphics and Symbols that are also used for other sorting architectures, and then symbols that can be detected by multiple levels are free. For this diagonal architecture, a lookup table can be derived and a technology described in the present invention can also be used, and such The application is also within the scope of the present invention. For the above example, it can be seen that: for the diagonal continuous interference cancellation architecture, the uniform distribution used to support the data transmission rate (that is, the two data streams Each data stream has a spectrum effect of L5 bps / Hz) The minimum required SNR is smaller than the minimum required SNR for the second rate group (ie, the spectral efficiency of '4/3 and 5/3 bps / Hz) The receiving SNR is about 0.6 dB higher. 1 This gain is achieved without seriously complicating the system design. In order to reduce the minimum receiving SNR required to achieve the target under a specific overall spectral efficiency, it may not be Reverses the error-free data stream of any previous reply The minimum possible spectral efficiency of the broadcast condition is assigned to the last reply data stream. If the spectral efficiency of the last reply data stream is reduced, 'the frequency efficiency of one or more previously reply data streams must be correspondingly increased' in order to obtain The specific overall spectral efficiency. The increased spectral efficiency of the previously returned data stream will then result in a higher required SNR. If the spectral efficiency of any previously returned data stream is increased too much, it is the data stream The required SNR determines the minimum received SNR, not the required SNR of the data stream that is finally replied to determine the minimum received SNr (this is the case of the average sentence distribution of the data transmission rate). In the above example, the second rate group requires A smaller received SNR, 14 疋 because it will not reverse the error of any of the first reply data stream 1 -30-200304307 Description of the invention continued page (27) One of the mispropagation conditions is assigned a smaller spectral efficiency Data stream 2 that was later responded to. For the first rate group, the spectral efficiency assigned to data stream 1 is too high +, so although this way guarantees There will be any error propagation, but this method reduces overall performance by forcing a higher spectral efficiency to be assigned to data stream 2. In contrast, the second rate group will still guarantee that there will be no errors A more practical spectral efficiency of propagation (but with lower trust than the first rate group) is assigned to data stream 1. As shown in Table 1, the margin of the data stream of the first rate group is 3.9 dB, and The margin of the data stream 1 of the second speed group is 1.4 dB. The technique described in the present invention can be used to determine the overall spectrum under a specific receiving snr (the SNR can be the working SNr of the MIMO system). A group of data transmission rates that maximizes efficiency. In this case, according to the specific received SNR, and using equation (7), a set of effective SNRs for Nτ data streams is determined. Then for each effective snr in the group, the highest spectral efficiency that can be supported by the effective SNR at the target PER is determined. This can be done using another lookup table that stores the values of the spectral efficiency and the associated effective SNR. A set of Nτ spectral efficiencies is obtained for the set of Nτ effective snr. Then, a group of data transmission rates corresponding to the Nτ spectral efficiency of the group is determined, and the group of data transmission rates can be used for the Nτ data streams. This rate group maximizes the overall spectral efficiency at this particular received SNR. In the previous description, the effective SNR of these data streams is determined based on the received SNR and using equation (7). As mentioned earlier, this equation includes several assumptions, and in a typical MIM0 system, these assumptions (to a considerable extent -31-(28) (28) 200304307 Continued Description of the Invention) are roughly true. In addition, the equation (7) is derived based on the use of the continuous interference cancellation processing at the receiver. It is also possible to use different parties or a look-up table to determine the validity of the data stream under different working conditions and / or receiver processing technologies, and such a decision method is within the scope of the present invention. . For simplicity of explanation, a floc transfer rate determination technique has been explicitly described for a MIM0 system. These technologies can also be used in other multi-channel communication systems. One 丨 丨 丨 _- One A broadband MIMO system may encounter selective attenuation of the frequency. Such selective attenuation is characterized by different attenuation amounts in the entire system bandwidth. The selective attenuation of the Wei frequency causes Intersymbol Interference (referred to as ISI). ISI is a phenomenon in which each symbol in a received signal becomes the interference of each subsequent symbol in the received signal. This interference degrades performance by affecting the ability to correctly detect the received signal. OFDM can be used to mitigate ISI, and / or OFDM can be used for other considerations. An OFDM system effectively divides the overall system bandwidth into several (nf) frequency sub-channels. The frequency sub-channels can also be referred to as sub-bands or frequency bins. Each frequency sub-channel is associated with a separate subcarrier on which data can be modulated. The frequency secondary channel of the 0FDM system may also encounter selective frequency attenuation. This situation depends on the special nature of the propagation path between the transmitting antenna and the receiving antenna (such as rQUltipath profile). When using OFDM, as is known in this technology, it is possible to reduce the frequency due to selective attenuation by repeating a portion of each OFDM symbol (that is, 'append a cyclic preamble to each OFDM symbol). Produced -32- (29) 200304307 Description of Invention Continued ISI. NF frequency sub-channels can be used for data in each space of 1 N / A sub-channels in the 1 MIM series T and none (that is, a MIMO-OFDM system) using OFDM. transmission. Each frequency channel of each sub-channel can be called a transmission channel, and there can be Np-Ns transmission channels between NT transmission antennas and Nr receiving antennas for data transmission. The method described above is performed, and the data transmission rate determination described above is performed for the ^ transmission antennas of the group. In an alternative embodiment, the data transmission rate determination may be performed for each of the nf frequency sub-channels in a manner independent of the group's Nτ transmission antennas. Figure 5 is a block diagram of a transmitter unit (500), which is an embodiment of the transmitter part of the transmitter system (110) shown in FIG. In a consistent embodiment, 'a single JL data transmission rate and coding and modulation architecture can be used for each such known data stream to be transmitted on Nτ transmission antennas (ie,' each antenna is used There are independent coding and modulation methods). The independent data transmission rate and coding and modulation architecture to be used for each transmission antenna can be determined according to the control provided by the controller (130), and these data transmission rates can be determined in the manner described above. The transmitter unit (500) includes ... a τχ data processor (n4a) that receives, encodes, and modulates each data stream according to an independent encoding and modulation architecture, so that Providing modulation symbols; and (2)

A TX MIMO processor (120a), and if 〇fdm is used, the TX MIMO processor (120a) can further process the modulation symbols in order to provide -33- 200304307 Invention Description Continued (30) transmission symbols. The TX data processor (114a) and the TX MIMO processor (120a) are an embodiment of the TX data processor (114) and the TX MIMO processor (120) shown in FIG. 1, respectively. In the specific embodiment shown in FIG. 5, the TX data processor (114a) includes a demultiplexer (510), Nτ encoders (512a-512t), Nτ channel interleavers (514a-514t), And Nτ symbol mapping elements (516a-516t) (that is, a set of devices in which each transmission antenna has an encoder, a channel interpolator, and a symbol mapping element. The demultiplexer (510) sends the communication data ( That is, information bits) demultiplexing ^ Nτ data streams of Nτ transmission antennas used for data transmission. These Nτ data streams can be associated with a number of different data transmission rates determined by rate control. Each data stream is provided to a separate encoder (512). Each encoder (512) receives a separate data stream and assigns the data stream to the data stream according to the specific encoding architecture selected for the data stream. Encoding to provide the encoded bits. The encoding increases the reliability of data transmission. The encoding architecture can include cyclic redundancy check (Cyciic Re (jun (janCy check; CRC), convolution code) 〇nai coding), 丨 Turbo coding, Any combination of coding architectures such as block coding. The encoded bits from each encoder (512) are then provided to a separate channel interleaver (514), and the channel interleaver (514) is to insert X into the encoded bits according to a specific interleaving I structure. The interleaving provides the diversity of time to the encoded bits, so it can be used according to the data stream. One of the transmission channels averages the SNR to transmit data, reducing signal attenuation, and further removing the correlation between the encoded bits used to form each modulation symbol. -34- 200304307 _ (31) Description of the invention continued page The encoded and interleaved bits from each channel interleaver (5 14) are provided to a respective symbol mapping element (516), which symbol mapping element (516) maps these bits, Modulation symbols are formed. The modulation control provided by the controller (130) determines the specific modulation architecture to be implemented by each symbol mapping element (5 16). Each symbol mapping element (5 16) gathers several groups of qi encoded and interleaved bits to form a non-binary symbol And the symbol mapping element (516) further maps each non-binary symbol to the selected modulation architecture (for example, QPSK, M-PSK, M-QAM, or some other so-called H architecture) Corresponding to a specific point in a signal constellation. Each mapped signal point corresponds to a Mj array (Mrary) modulation symbol, where Mj corresponds to the specific selected for the j-th transmission antenna. Modulation architecture, and Mj = 2qj. The symbol mapping elements (516a-516t) then provide modulation symbols for Nτ data streams. In the specific embodiment shown in FIG. 5, the TX MIMO processor (120a) includes Nτ OFDM modulators, and each OFDM modulator includes an Inverse Fast Fourier Transform (IFFT) unit ( 522) and a cyclic preamble generator (524). Each IFFT unit (522) receives a respective modulated symbol stream from a corresponding symbol mapping element (516). Each IFFT unit (522) aggregates several sets of NF modulation symbols to form a corresponding modulation symbol vector, and uses inverse fast Fourier transform to convert each modulation symbol vector to its time domain representation (the time The domain representation is called an OFDM symbol). The IFFT unit (522) may be designed to perform the inverse transform on any number of frequency sub-channels (eg, 8, 16, 32, ..., NF frequency sub-channels). For each OFDM symbol, the cyclic preamble generator (524) repeats a part of the OFDM symbol -35 · 200304307_ (32) Description of the continuation page to form a corresponding transmission symbol. The cyclic preamble ensures that each transmission symbol can maintain its orthogonality when multi-path delay dispersion occurs, thereby improving resistance to adverse path effects such as channel dispersion caused by selective attenuation of frequencies. A cyclic preamble is generated (524) and a transport symbol stream is provided to an associated transmitter (122). If OFDM is not used, the TX MIMO processor (120a) need only provide the modulation symbol stream from each symbol mapping element (516) to the associated transmitter (122). Each transmitter (122) receives and processes a separate modulation symbol stream (for MIMO without OFDM), or receives and processes a separate transmission symbol stream (for MIMO with OFDM) in order to generate A modulated signal is then transmitted from the associated antenna (124). Other designs for the transmitter unit may also be implemented, and such other designs are also within the scope of the present invention. The following U.S. patent applications further describe the encoding and modulation of the MIMO system with and without OFDM: • U.S. patent application 09 / 993,087, Multiple-Access Multiple-Input, filed on November 6, 2001 Multiple-Output (ΜΙΜΟ) Communication System "; • US Patent Application 09 / 854,235 filed on May 11, 2001 " Method and Apparatus for Processing Data in a Multiple-Input Multiple-Output (ΜΙΜΟ) Communication System Utilizing Channel State Information ”; • Two-36-200304307 filed on March 23, 2001 and September 18, 2001 _ (33) Description of the invention continued on US Patent Application 09 / 826,481 with the same invention name and 09 / 956,449 " Method and Apparatus for Utilizing Channel State Information in a Wireless Communication System "; • US Patent Application 09 / 776,075" Coding Scheme for a Wireless Communication System "filed on February 1, 2001; and • U.S. Patent Application filed on March 30, 2000 2 “High Efficiency, High Performance Communication Sy & lam Employing Multi-Carrier Modulation” o All of these patent applications are assigned to the assignee of this patent application, and this patent application is hereby cited for reference . Patent application 09 / 776,075 describes an encoding architecture in which data can be encoded with the same basic code (such as a convolutional code or a full-round code), and bit deletion is adjusted to achieve the required data transmission rate , So you can get different data transmission rates. Other coding and modulation architectures can also be used, and such usage is also within the scope of the present invention. Receiver System Figure 6 is a block diagram of an RX MIMO / data processor (160a) that can implement a continuous cancellation receiver processing technique. The RX MIMO / data processor (160a) is an embodiment of the RX MIMO / data processor (160) shown in FIG. Each of the NR antennas (152a-152r) receives signals transmitted from Nτ transmission antennas, and these signals are routed to a respective receiver (154). Each receiver (154) adjusts (eg, filters, amplifies, and downconverts) a respective signal received, and digitizes the adjusted signal to provide a corresponding information-37- 200304307 (34) Description of the invention Continuing sample flow. For MIMO without OFDM, these data samples represent the received symbols. Each receiver (154) then provides a received individual symbol stream to the RX MIMO / data processor (160a), and the received individual symbol stream contains a symbol received during each symbol. For MIMO using OFDM, each receiver (154) further includes a cyclic preamble removal element and an FFT processor (for simplicity, these two devices are not shown in Figure 6). The cyclic preamble removal element removes the cyclic preamble previously inserted by the transmitter system for each symbol transmitted in order to provide a corresponding received OFDM symbol. The FFT processor then transforms each received OFDM symbol to provide a vector of NF received symbols during the symbol period to the NF frequency sub-channels. The NR receivers (154) then provide the NR received symbol vector streams to the RX MIMO / data processor (160a). For MIMO using OFDM, the RX MIMO / data processor (160a) can demultiplex these> ^ received symbol vector streams into NR received symbol streams of the NF group, one for each frequency channel The group of received symbol streams, and each group of received symbol streams includes> ^ received symbol streams of one frequency sub-channel. The RX MIMO / data processor (160a) may then process the NR received symbol streams of each group in a similar manner to the above processing of 1 ^ received symbol streams for MIMO without OFDM. As is known in the art, the RX MIMO / data processor (160a) can then also process the received signal for MIMO using OFDM according to some other sequencing architecture. In either case, the RX MIMO / data processor (160a) processes the NR received symbols -38- 200304307 (35) I Invention description Continuation page stream (for MIMO without OFDM), or Nr number of each group Receive symbols (for MIMO using OFDM). In the embodiment shown in FIG. 6, the RX MIMO / data processor (160a) includes a right-handed (ie, cascaded) receiver processing stage (61a-61n), where each of the A transmitted data stream has one level. Each receiver processing stage (61) (except the last stage (61 On)) includes a space processor (620), an RX data processor (630), and an interference canceller (640). This last stage (610η) includes only the space processor (62〇11) and the rx data processor (63〇n). _

For the first stage (610a), the space processor (62a) receives> ^ symbol streams (represented as L1) from the receivers (154a-154r), and according to a specific space or Shiba-time The receiver processing technology processes these Nr received symbol streams' in order to provide (up to) ^ detected symbol streams (denoted as another 1). For MIMO using OFDM, the nr received symbol streams contain the received symbols of a frequency sub-channel. Select the detected symbol stream S i corresponding to the lowest data transmission rate, and provide the detected symbol stream to RX; the shell processor (630a), β processor (630a) for further processing (ie, demodulation, decoding (Inserting and decoding) The detected symbol stream is selected for the first stage to provide a decoded data stream. The space processor (62a) further provides an estimate of the channel response matrix Η, and this estimate is used to perform all levels of space or space-time processing. For the first stage (61a), the interference canceller (64a) also receives NR received symbol streams from the receiver (154) (i.e., the vector is also 1). The interference canceller (640a) further receives the decoded data stream from the RX data processor (63〇a) and performs processing (such as encoding, interleaving, modulation, and channel response, etc.) to -39- 200304307 (36) According to the invention, the stomach is obtained as nr re-modulated symbol streams (represented as i1) of the interference component estimates generated by the data stream just returned. Then the sub-modulated symbol stream is subtracted from the input symbol stream of the first stage in order to derive nr modified symbol streams (represented as a vector X2). The modified symbol stream includes the All interference components except interference components. These NJ® modified symbol streams are then provided to the next level. For each of the second to last stages (610b-610n), the space processor of that stage receives and processes j ^ R modified symbol streams from the interference canceller in the previous stage in order to derive the stage Detected symbol stream. The RX data processor selects and processes the detected symbol stream corresponding to the lowest data transmission rate on the stage in order to provide a decoded data stream on that stage. For each of the second stage to the last second stage, the interference canceller in this stage receives Nr modified symbol streams from the interference canceller in the previous stage and from the RX data processor in the same stage The decoded data stream, and then derive NR re-modulated symbol streams, and provide NR modified symbol streams to the next stage. The U.S. patent applications 09 / 993,087 and 09 / 854,235, cited above, further describe the process of receiver processing in detail. The space processor (620) in each stage implements a specific space or space-time receiver processing technology. The specific receiver processing technology to be used usually depends on the characteristics of the MIMO channel, and the MIMO channel is characterized by whether it can be right or wrong Non-dispersive or dispersive. Non-dispersed MIMO channels will have flat attenuation (that is, approximately the same amount of attenuation across frequency bands of the entire bandwidth), and distributed MIMO channels will have frequencies of -40- 200304307 ___ (37) Selective attenuation (for example, each frequency section of the entire bandwidth has a different amount of attenuation). For a non-decentralized MIMO channel, the received signal can be processed using spatial receiver processing techniques to provide a detected symbol stream. These spatial receiver processing technologies include Channel Correlation Matrix Inversion (CCMI) technology (also known as zero-forcing technology) and Minimum Mean Square Error (MMSE) technology. Other space receiver processing technologies can also be used, and these technologies are also within the scope of the present invention. For a decentralized MIMO channel, time dispersion in the channel introduces inter-symbol interference (ISI). To improve performance, a receiver attempting to reply to a particular data stream being transmitted will need to improve interference (or "crosstalk") from other data streams being transmitted, and ISI from all data streams. To reduce crosstalk and ISI, space-time receiver processing techniques can be used to process the received signal to provide a detected symbol stream. These space-time receiver processing techniques include MMSE Linear Equalizer (MMSE-LE), Decision Feedback Equalizer (DFE), and Maximum-Probability Sequence Estimator (Maximum- Likelihood Sequence Estimator »(MLSE for short). These CCMI, MMSE, MMSE-LE, and DFE technologies are described in detail in the previously cited U.S. patent applications 09 / 993,087, 09 / 854,235, 09 / 826,481, and 09 / 956,449. The data transmission rate determination and data transmission techniques described in the present invention can be implemented in various ways. For example, these techniques can be implemented in hardware -41- 200304307 _ (38) Invention Description Continued, Software, or a combination of both. For a hardware embodiment, one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), and digital signal processing devices (Digital Signal Processors) Processing Device (DSPD for short), Programmable Logic Device (PLD for short), Client-Programmable Gate Array (FPGA), processor, controller, microcontroller, microprocessor , Other electronic units designed to perform the functions described in the present invention, or components implemented in a combination of the above to determine the data transmission rate on the transmitter and the data transmission on the transmitter / receiver. For a software embodiment, the modules (such as programs and functions) that can be used to perform the functions described in the present invention implement certain aspects of data transmission rate determination and processing on the transmitter / receiver. The software code may be stored in a memory unit (such as the memory (132) shown in FIG. 1) and executed by a processor (such as the controller (130)). The software code may be within the processor or processed The memory unit is implemented outside the processor, and in the case of being implemented outside the processor, the memory unit is communicatively coupled to the processor via various devices in a manner known in the art. This article contains Some headings are for reference and help to find certain paragraphs. These headings are not intended to limit the concepts described under those headings, and they can be applied to other paragraphs throughout the specification. The foregoing descriptions of the disclosed embodiments are provided to enable those skilled in the art to make or use the invention -42- (39) \ (39) \ 200304307. Those skilled in the art will readily make various modifications to these embodiments. And, without departing from the spirit and scope of the present invention, the general principles defined by the present invention can be applied to other embodiments. Therefore, the present invention will not be limited to the embodiments shown herein Rather, it will be applied to the broadest scope consistent with the principles and innovative features disclosed by the present invention. Brief description of the drawings If you refer to the detailed descriptions above and cooperate with the drawings, it will be easier to understand the temple of the present invention Features, essence, and advantages'. In these drawings, the same code marks the corresponding parts in all the drawings, these drawings are: Figure 1. A transmitter system and a receiver system in the MIMO system. A block diagram of an embodiment; FIG. 2 is a flowchart of a successive interference cancellation receiver processing technique for processing ^ received symbol streams in order to reply Nτ transmitted symbol streams; FIG. 3 is a decision to support a A flowchart of one embodiment of a procedure for minimum received SNR required for a particular group of data transmission rates; FIG. 4 is a diagram of a 1,4 / 3, 5/3, and 2 in a {1,4} ΜΙΜΟ system; Figure 5 is a diagram showing the relationship between the packet error rate and SNR under the spectral efficiency of bps / Hz; Figure 5 is a block diagram of an embodiment of a transmitter unit; and Figure 6 is a reception that can implement a continuous interference cancellation receiver processing technology Machine unit A block diagram of one of the embodiments. Symbol representation of the diagram 100 MIMO system 110 Transmitter system 150 Receiver system-43- 200304307 Description of the invention continued (40) 112 Source 114, 114a Transmission data processor 130, 170 Controller 120J_20a 122, 122a -122t, transmission MIMO processor 154a-154r 124a-124t, 124, 152, transmitter 152a-152r antenna 154 receiver-160, 160a reception MIMO / data processor 178 transmission data processor 180 modulator 140 demodulator 142 Receive data processor 132, 172 Memory 500 Transmitter unit 510 Demultiplexer 512, 512a-512t Encoder 514, 514a-514t Channel interleaver 516, 516a-516t Symbol mapping element 522, 522a-522t Fast Inverse Fourier transform unit 524, 524a-524t Cyclic preamble generator 610, 610a-610n Receiver processing stage 640, 640a-640n Interference canceller 620, 620a-620n Space processor 630, 630a-630n Receive data processor- 44-

Claims (1)

Method of data transmission rate of multiple data streams in a multi-channel communication system 200304307. Patent application scope 1 · A method for determining a plurality of data streams to be transmitted via an output channel, including the following steps: Deciding to be used for such plural data Each of the multiple data transmission rates of a data stream—the data transmission rate—must be equal to noise and noise and interference (SNR), at least two of which have different data transmission rates; based in part on a receiver Determining the effective SNR of each of the data streams for each of the data streams; and comparing the required SNR of each data stream with the effective SNR of the data stream; and Whether the plurality of data transmission speeds are supported is determined according to the result of the comparison. 2. The method according to item 1 of the patent application scope, wherein the plurality of data streams are transmitted via a plurality of transmission antennas in a multiple-input multiple-output (MIMO) communication system. 3. The method according to item 2 of the patent application park, wherein each data stream is transmitted via a separate transmission antenna, and the effective SNR of each data stream is determined according to the full transmission power used for the data . 4. The method according to item 1 of the scope of patent application, wherein the effective SNR of each data stream is further determined according to the receiving SNR used to indicate the working conditions of the plurality of transmission channels. 5. The method according to item 4 of the scope of patent application, which is based on the multiple transmission method speed ratio stream flow rate to enter the transmission stream. The required SNR of one of the data streams in the 200304307 patent application continuation page data stream It is decided to receive snr. For example, method 4 of the scope of the patent application, wherein the receiving SNR is specified for the communication system. For example, method 4 of the scope of patent application, wherein the received SNR is estimated at the receiver. 8. The method according to item 4 of the scope of patent application, wherein the continuous interference cancellation process returns a data stream at each level, and wherein the effective SNR of each reply data stream is estimated as: SNR ,, SNRcff (fc) Equation (9) where SNReff (k) is the effective SNR of the data stream returned in the k-th stage, SNRrx is the received SNR, NR is the number of transmitting antennas used for data transmission, and Nr is the number of receiving antennas number. 9. The method according to item 4 of the patent application scope, further comprising the steps of: evaluating the data transmission rate of the complex array; and selecting a rate group associated with a minimum received SNR for use in the plurality of data streams. 10. The method according to item 9 of the patent application scope, wherein the data transmission rate in the per / rate group is selected so as to obtain a specified overall spectral efficiency. 11. The method according to item 1 of the patent application scope, wherein the required SNR for each data transmission rate is determined according to a deafness inquiry table. 12. If the method of claim 1 is applied, if the required SNR of each data transmission rate is less than or equal to the effective SNR of the data transmission rate -2- 200304307 Application for a continuation of the scope of the patent application, it shall be regarded as the plurality of data 13. Rushen nasal brake r ^ ten transmission rate is supported by six or eight t heart Wanfa, of which the Tongshu Man-Frequency Multiplexing (OFDM). ⑷A method for deciding the transmission rate of a complex material transmitted by a plurality of transmitting antennas when one or one is called / into multiple inputs ... determined to indicate a working condition of the MIM0 system Signal and noise and interference ratio (SNR); ^ decided to be used for the plurality of these data streams; one of the transmission rate must be SNR, among which the transmission rate is different And in which the material transfer rate is selected so as to obtain a specified overall spectrum] According to the working SNR and a continuous interference cancellation processing technique performed on a receiver to return a data stream, each of the plurality of data streams One of the effective SNRs of the data stream; The necessary SNR of each data stream is determined with the data stream and whether the plurality of data is supported according to the result of the comparison. 15 ·-A kind of data used to determine whether to communicate through a multi-channel The data transmission of the multiple data streams transmitted in turn in the system is supplemented by the following steps: · Deciding to indicate the receiving SMR of the multiple transmission channels; the system implementation is in progress (ΜΙΜΟ) One of the information of the communication data stream, the working data transmission rate of at least two of these multiple ratings; one of the methods of determining the multiple transmission rates of the Γ-effect SNR comparison data transmission rate based on the multiples. 200304307 Continuation of the scope of patent application according to the information flow of material stream. According to the material transfer wheel 16. If the application information, the information 17. Specify if the application 18. If so, please enter multiple each. 19. One of the following decisions in the memory line Each (SNR) of the channel, each of which is partially executed, will receive the SNR and A on a receiver in order to reply to the plural two consecutive interference cancellation processes, and determine the complex number once 1 4 1 ^ Each of the three spoons has one effective SNR for each data stream; and _ the effective SNR of the data stream depends on> one of the prevalence of a data stream, at least two of these data, Ding will lose the rate. The method of the 15th item of the profit range, where ^ private a /, determines the data rate of each data stream, so that the 7 SNR of the data stream is less than or equal to the effective SNR. item Method, in which you receive the SNR for the Tongji system t. The method of item 15 of the boxing range, in which Bo Huizhong uses a multiple-input-output (ΜΙΜΟ) communication system to transmit antennas in each valley. And the communication of the stream of materials. Communication is combined with a digital signal virtual processing device (DSPD), the digital signal processing device can interpret the number of shots # π $ double-bit information, in order to perform less: will use One of a plurality of data transmission rates of a plurality of data streams to be transmitted via a plurality of transmissions in a multi-channel communication system. One of the data transmission rates must be a signal-to-noise and interference ratio of at least two of which are different. According to a receiver, in order to respond to the successive interference cancellation processing of the plurality of data streams, one of the plurality of data stream data streams is determined to have an effective SNR; a data stream must have an SNR and an effective snr of the data stream. Comparison -4- 200304307 continued patent application range; and based on the results of the comparison, determine whether the data transmission rate of the Temporal Percent Slavery 疋 疋 疋 Tenji a Temple is supported. 20 · —A device in a multi-channel communication system, including ... · a component that determines the necessary signal-to-noise and interference ratio (SNR) to determine a plurality of data that will be used to be transmitted via a plurality of transmission channels The SNR of each data transmission rate of the multiple data transmission rates of the stream must be SNR. At least two of these data transmission rates are different. The component that determines the effective SNR is used in part to respond to the The continuous interference cancellation processing performed while waiting for a plurality of data streams determines a valid snr of each of the plurality of data streams; a comparison component for comparing the necessary SNR of each data stream with the validity of the data stream SNR comparison; and a component that determines whether the plurality of data transmission rates are supported according to the result of the comparison. 21. The device of claim 20 of the patent application park, further comprising: an evaluation component for evaluating the data transmission rate of the complex array; and a selection component for selecting a rate group associated with a minimum received SNR so that Used for these multiple data streams. • Sigma A asks for the device of Patent Fanyuan Item 20, in which the multi-channel communication system is a multi-input multiple-output (ΜΙΜΟ) communication system. 23. The device according to item 22 of the patent application park, wherein the MIMO system implements orthogonal frequency division multiplexing (OFDM). 24. A base station including a device in the scope of patent application No. 20. 200304307 Application for patent application park continuation pages 25.-26. — The number of devices is equal to the number 27 — such as a wireless terminal that contains the device in the scope of the patent application. A transmitting unit in a multiple-input multiple-output (ΜΙΜΟ) communication system includes: a controller 'The controller is operable to perform the following steps to determine a plurality of data streams S to be transmitted through a plurality of transmission antennas Material transmission rate: each data transmission rate must be equal to 3 or more data transmission rates-a required signal-to-noise and interference ratio (SNR), of which at least two cores φ data transmission rates are different; " partly based on A receiver determines the effective SNR of each data stream of the plurality of data streams in order to reply to the continuous interference cancellation processing technology subscribed to the plurality of data streams; The effective SNR comparison of the streams and whether or not the plurality of data transmission rates are supported are determined according to the results of the M comparison. Lu Yi transmission (TX) data processor, the τχ data processor can work and has the data determined by the child. Each data stream at a transmission rate to provide a separate symbol stream; and one or more transmitters that can operate to process The plurality of symbol streams of the plurality of data streams provide a plurality of modulated signals suitable for transmission via the plurality of transmission antennas. The transmitter unit of the scope of patent application No. 26, in which the controller can work in one step and determine the data transmission rate of the plurality of data streams of the patent application scope by performing the following steps: " 平Estimate the data transmission rate of the array; and select a rate group associated with a small received SNR. 28 · —A base station including a transmitter unit in the scope of patent application No. 26. Kind of dagger; wireless terminal of the transmitter unit of the patent application No. 26. 30. A transmitter device in a multiple-input multiple-output (MIM〇) communication system, comprising: a means for determining the required signal-to-noise and interference ratio (SNR) to determine which components One of the data transmission rates of the plurality of data transmission rates of the plurality of data streams transmitted by the plurality of transmission antennas in the MIM〇 system must have an SNR, of which at least two of these data transmission rates are different; A component for determining one of each data stream of the plurality of data streams to be effectively captured according to a partial interference cancellation process performed on a receiver in order to reply to the plurality of data streams. Comparison means for comparing the necessary SNR of each data stream with the effective SNR of the data stream; a means for determining whether the plurality of data transmission rates are supported according to the result of the comparison; a means for processing the data stream, for Process each ancestor, * ,, t Λ stream to provide a separate symbol stream; and a component that processes the symbol stream 'to process the plurality of symbol streams of the plurality of data streams in order to provide The plurality of modulated signals are transmitted by the search antenna, and the 200304307 patent application continues to transmit the plurality of modulated signals. 31 · —A receiver unit in a multiple-input multiple-output (MIM〇) communication system, comprising: a receiver (RX) MIMO processor, the rx MIMO processor is operable to receive a plurality of received symbol streams And use continuous interference cancellation processing technology to process the plurality of received symbol streams in order to provide a plurality of detected symbol streams of a plurality of transmitted data streams, wherein each stage of the continuous interference cancellation process has a detected data stream And an RX data processor, the Rx data processor is operable to process each detected symbol stream in order to provide a corresponding decoded data stream, and the plurality of transmissions are determined by performing the following steps The data transmission rate of the data stream: determine the received signal to noise and interference ratio (SNR), which is used to indicate one of the working conditions of the communication system; determine the plurality of these based on the received SNR and subsequent interference cancellation processing. Each stream of data is effective SNR; and the data transmission rate of each data stream is determined according to the effective anti-hank, and at least two of them should be The data transmission rate is different.